The most effective ones tend to combine several emissions-cutting strategies, not a stand-alone approach, according to an examination of 1,500 policies globally.
First, the good news: 1,500 climate policies aimed at reducing emissions of planet-warming greenhouse gases have been implemented across dozens of countries over the past two decades.
The more troubling news: Only around 4 percent may have substantially reduced emissions, according to a new study.
“We’re finding good and bad news together,” said Nicolas Koch, a climate economist at the Potsdam Institute for Climate Impact Research and a co-author of the study published Thursday in Science. “It’s highlighting opportunities, like that larger reductions are possible, but also challenging the political will for policy design.”
While 63 policies highlighted in the study successfully reduced as much as 1.8 billion metric tons of carbon, the United Nations estimates that emissions must fall by 23 billion metric tons by 2030 to reach targets laid out in the 2015 Paris Agreement. Those targets aimed to limit the increase in the global average temperature to 1.5 degrees Celsius, or 2.7 degrees Fahrenheit, in order to preserve a livable planet.
With less than a decade left before that benchmark, the research could provide models for the best paths forward. “There is no silver bullet policy solution for climate mitigation,” said Jonas Meckling, an associate professor at University of California Berkeley and a climate fellow at Harvard Business School.